ML20005F148

LER 89-042-00:on 891209,inadvertent Actuation of Control Room Emergency Ventilation Sys Occurred.Caused by Keying of Hand Held Radio in Vicinity of Chlorine Monitors by Technician.Technician counseled.W/900108 Ltr

ML20005F148
Person / Time
Site:	Arkansas Nuclear
Issue date:	01/08/1990
From:	Ewing E, Millar D ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1CAN019003, LER-89-042, NUDOCS 9001120354
Download: ML20005F148 (4)

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{ Arkansas Power & Ught Company i

,*, v j ArAansas Nuclear One Raate 3. Ib 137 G l

AussoN%e. AR 70B01 i Tel 501964 3103

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January 8,_1990 1CAN019003 U.S. Nuclear Regulstory Commission '

Document Control Desk l Mail Station PO-137 Washington, D.C. 20555

SUBJECT:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 Licensee Event Report 50-313/89-042-00 t

Gentlemen:

In accordance with 10CFR50.73(a)(2)(iv) attached is the subject report concerning an inadvertent actuation of the Control Room Emergency Ventilation System initiated by a trip of the chlorine monitors caused by a personnel error.

Very truly yours, "E. C.' Ewing General Manager, Technical Support and Assessment ECE/DM/aw

, cc: Regional Administrator '

L Region IV O.S. Nuclear Regulatory Commission Gil Ryan Plaza Drive, suite 1000 Arlington, TX 76011

INPO Records Center 1500 Circle 75 Parkway

! Atlanta, GA 30339-3064 l

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NRC Fors 366 U.S. Nuclear Regulatory Commission (9 83)- Approved OMB hp. 3150-0104 ,

LICEN$EE EVENT REPORT (L E R)

FACILITY NAME (1) Arkansas Nuclear One, Unit One lDOCAET NUMBER (2) lPAGE (3) ,

_ 10151010101 31 11 Sl110Fl013 TITLE (4) Inadvertent Actuation of the Control Room Emergency ventilation Systen Initiated by a Trip of the Chlorine Monitors Caused by a Personnel Error

. EVENT DATE (b) i LER NUBSER (6) i REPORT DATE 0 ) l OTHER F ACJLITIE$ INVOLVED (6) l l l l l$equentiall lRevisioni l l l l l Monthi Day IYear lYear l' I Number I l Number IMonth! Day lYear I Facility Names IDocket Number (s) l l l l l l l l l l l ANO. Unit 2 10lSIOl0101 31 6 8

_11 21 01 91 81 91 al 91--I 0 1 41 2 l--I O l 0 l of 11 O! 81 91 Of 10t41010101 i OPERATING l lTHIS REPORT 15 $UBMITTED PURSUANT TO THE REQulREMENTS OF 10 CFR 5:

MODE (9) i NI (Check one or more of the followino) (11)

POWEkl l_ l 20.402(b) l _t 20.40b(c) 1,xt 60.73(a)(2)(iv) l_l 73.71(b)

LEVELl l _ l 20.406(a)(1)(1) l_ l 50.36(c)(1) l_ I 50.73(a)(2)(v) l_I 73.71(c)

(10) 1010101 l 20.405(a)(1)(11) l_ l 60.36(c)(2) l_l 60.73(a)(2)(v11) l_l Other ($pecify in l _ l 20.40$(a)(1)(111) l_l 50.73(a)(2)(1) 1,,,1 50.73(a)(2)(v111)(A)l Abstract below and l_ l 20.405(a)(1){1v) l_ l 50.73(a)(2)(11) l_ l 50.73(a)(2)(viii)(B)l in Text. NRC Form i I 20.405(a)(1)(v) I l 50.73(a)(2)(111) I l 50,73(a)(2)(x) i 3664)

LICEN$f f CONTACT FOR THl$ LER (12) heae l Telechone Number t (Area l Dana Millar, Nuclear $afety and Licensing Specialist ICode l 1610111916!41-18111010 CONPLETE ONE LINE FOR EACH COMPONENT F AILURE DESCRIBED IN THIS REPORT (13) l l lReportabiel l l l l lReportabiel Causelsysteel Component IManufacturert to NPRDS I ICauselsysteel Component IManufacturert to NPRD$ 1 l I l l l l l l 1 I i i I i I I I I I I l i I 1 l 1 I I I I I I I I I l

'l l l l l l l l t  ! I l I I I I I l l I I I 1 1 I I l ! I I I I I I I SUPPLEMEN" REPORT EXPECTED (14) i EXPECTED l MonthI Day Iveer l $UBMIS$10N l l l

!Yi Yes (If yes. complete Exoocted subeission Date) !l No l

l DATE (15) l Of Il 21 21 91 0 .

ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines) (16) l l On December 9, 1989 at approximately 2004 hours0.0232 days <br />0.557 hours <br />0.00331 weeks <br />7.62522e-4 months <br />, an inadvertent actuation of the Control Room Emergency

! Ventilation System (CREVS) occurred. The CREVS actuation was caused by the Arkansas Nuclear One, Unit Two chlorine monitors tripping. A hand held radio was keyed in the vicinity of the monitors causing i l

the monitors to trip and initiate the actuation of the CREVS, The system actuated as designed. After determination that the actuation was spurious, the chlorine monitors were reset and the ventilation system was returned to normal. Since no actual high chlorine concentration existed, and because the CREV5 actuated as designed, there was no safety significance related to this event. The individual who keyed the hand held radio in the vicinity of the chlorine monitors has been counselled regarding the use of radios in the restricted area. As a result of previous inadvertent CREVS actuations, several system enhancements have been completed. Additionally, an engineering evaluation of the system design was previously initiated to determine if additional corrective actions are neces.ary. This event is being reported pursuant to 10CFR50.73(a)(2)(iv), as an event that resulted in an automatic actuation of an Engineered Safety Features systes.

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O Ferrn 1062.01B

' NRC Form M6A U.S. Nuclear Negulatory Commission (9-83) Approved 04B No. 3150-0104 Expires: 8/31/85 LICENSEE EVENT REPORT (LER) TEKT CONTINUATION FACILITY MME (1) (DOChET NUMB 1R (2) l t(R NUMBfR (6) i PAGE (3)

! I i 15equentiell IRevisioni 1 Arkansas Nuclear One, Unit One i 1.Yearl i Number l Number i l

10151010101 31 11 31 81 91--t 0 t al P t-- 01 0 101210Fl013 l TEXT (If more space is required, use additional NRC f orm 366A's) (17) l A. Plant Sta',us l

l At t.he time of occurrence of this event, Arkansas Nuclear One Unit One (AND 1) was in Cold Shutdown.  !

A mid-cycle outage was in progress. Arkansas Nuclear One, Unit Two (ANO 2) was at one hundred percent 1 of rated thermal power, Mode 1 (Power Operation). l B. Event Description On December 9,1989 at approximately 2004 hours0.0232 days <br />0.557 hours <br />0.00331 weeks <br />7.62522e-4 months <br />, an inadvertent actuation of the Control Room Emergency ventilation System (CREVS) (VIJ occurred.  !

The CREYS is designed to maintain habitability of the AND 1 and ANO-2 Control Rcom by automatically isolating the nomal Control Room ventilation system and starting upon receipt of an indication of high radiation or high chlorine concentration. The system consists of two redundant filter trains, both of which are located outside the ANO-1 section of the Control Room. Each filter train includes a centrifugal fan, roughing filter, en absolute filter and charcoal adsorbant. The CREV5 trains are nomally isolated from the Control Room by isolation dampers. System actuation instrumentation consists of two quick acting chlorine detectors located in the noma) ventilation supply duct for ANO-1 and two additional detectors at the ANO-2 supply air duct. Also, there is an area radiation monitor located in the AND-1 Control Room area and a process radtation monitor located in the ANO 2 nomal ventilation system outside air intake ductwork. An actuation signal from any of these instruments will initiate operation of the CREYS.

The CREV5 actuation which occurred on December 9,1989, was caused by the ANO-2 chlorine monitors 2CLS-8762 2 and 2CLS-87631 tripping. The system actuated as designed. After determination that the actuation was spurious, the chlorine monitors were reset and the ventilation system configuration was returned to normal.

C. Safety Significance Since no actual high chlorine concentration existed, and because the CREV5 actuated as designed, there was no safety significance related to this event.

D. Root Cause The chlorine monitor trips which initiated the actuation were caused by the keying of a hand held radio in the vicinity of the chlorine monitors by a Health Physics Technician. The area in the j vicinity of the chlorine monitors is posted to prohibit the use of hand held radios since testing i

and previous actuations have proven them to be sensitive to radio frequency interference. Therefore, I this event was the result of personnel error. The root cause of this event, however, is directly related to system design. The extreme sensitivity of the chlorine monitors coupled with the

, actuation logic which requires only one monitor to trip to initiate the CREV5 makes the system l highly susceptible to inadvertent actuations, l E. Basis for Reportability l

This evert is being reported pursuant to 10CFR50.73(a)(2)(iv), as an event that resulted in an automatic actuation of an Engineered Safety Features system. The ncn emergency event was also reported pursuant to 10CFR50.72(b)(2)(ii) on December 9, 1989 at 2050 hours0.0237 days <br />0.569 hours <br />0.00339 weeks <br />7.80025e-4 months <br />.

F. Corrective Actions The Health Physics Technician who keyed the hand held radio in the vicinity of the chlorine monitors has been counselled regarding the use of radios in the restricted area. Additionally, a memorandum has been issued to Health Physics personnel to emphasite the importance of not using radios in the vicinity of the chlorine monitors. A memorandum has been previously issued to inform plant personnel of the events involving the effects of radio frequencies on the chlorine monitors and to ensure personnel are cognizant of the restriction on the use of hand held radios in this area.

A radio frequency (RF) filter will be placed around the chlorine monitors to provide shielding of the signals which are generated by hand held radios. A schedule for this modification will be provided to the NRC by January 22, 1990.

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.o Form 1D62.01B NRC Fors 366A U.S. Nuclear Regulatory Commission (9-83) Approved DMB No. 3150-0104 Empires: 8/31/85 LICENSEE EVEMT REPORT (LER) TEXT CONTINUATION FACILITY NAME (1) lDOCAET NUMBER (2) i LER NUMBER (6)

Arkansas Nuclear One, Unit one l l l 15equentiell IRTiisiElPAGE(3) l l l Yearl i Number i i Number l 10151010101 31 11 31 81 91- I 0 t at t 1--I O 1 0 101310F1013 TEXT (If more space is required, use aeditions) NRC f ore 366A's) (17)

As a result of previous inadvertent actuations, several system enhancements have been completed (see LER 50 313/89-009-01). Additionally, an engineering evaluation of the system '

design was initiated to determine if additional corrective actions are necessary. This '

evaluation is planned to be completed by March 31, 1990.

C. Additional Infor1 nation Previous inadvertent CREV5 actuations were reported in LERs 50-313/89 009-01, 50 313/89-011 00, 50-313/99 014 00, 50-313/89 025-00, 50-313/89 035-00 and 50-313/89-036-00.

Energy Industry 16entification System (E!!$) codes are designated in the text as [XX).

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